Product Review

Baader Planetarium Narrowband H-Alpha 7nm, 2"

Delivering the absolute highest contrast deep sky images in H-Alpha, H-Beta, Oxygen III, and Sulfur-II, Baader Planetarium's Premium Narrowband CCD passfilters are a must have when it comes time to excellent photography and observation. With the shortest exposures possible, the ultra-narrow bandwidths have extremely high transmission while completely rejecting light pollution and blocking longer wavelengths. Baader's high optical quality narrowband filters guarantee no loss in sharpness or contrast making it a superb filter that is a must have for enthusiasts collections.

Delivering a smooth and accurate 1/4 wavefront over the entire surface, each substrate is fine-optically polished delivering exceptional performance. The special custom polishing operation Baader executes on all Narrowband passfilters is the difference when comparing standard commercially precision polished filter substrates most all other filter manufacturers use.

In the production process of the Baader Narrowband CCD passfilters consideration of eliminating the annoying reflections present in other narrowband astro-filters was a key component in the creation. In order to succeed in assuring freedom from reflections, Baaders production process required careful design and testing of the coating stacks to ensure such excellence amongst each narrowband passfilter.

The applications of coatings on all Baader products are professionally applied in Germany by the most sophisticated equipment available today. This application process ensures high consistency for bandpass centering, out of band blocking, and transmission. These anti-reflection coatings are designed to avoid halos as well as balanced to prevent physical deformation of optically flat substrates. Baader's Narrowband CCD passfileters have ultra-hard ionbeam deposition which ensures coatings to never degrade from use or normal cleaning. In order to guarant